1. Field of the Invention
The present invention relates to a surgical manipulator system which is designed to insert a medical device such as an endoscope into a body cavity of a subject for the purpose of examining the interior of the cavity and performing surgery within the cavity.
2. Description of the Related Art
Hitherto, transcutaneous endoscope surgery in which an endoscope or a medical instrument is inserted into a body cavity through a hole cut in the body wall (e.g., the abdominal wall) to perform various treatments in the body cavity has been known. This is because transcutaneous endoscope surgery involves no large-scale incision and is therefore scarcely invasive to the patient. This type of surgery is now widely performed to extract the gallbladder or a part of either lung.
A surgical manipulator is known which holds an endoscope or a medical instrument and which a surgeon can remote-control to manipulate the endoscope or the instrument in performing a surgical operation. A surgical manipulator of this type has manipulators and an insertion section for holding an endoscope or a medical instrument. The insertion section is a multi-joint structure, having a plurality of rods joined together. The actuators drive the rods, respectively, so that the insertion section may smoothly approach an object within a body cavity.
To perform a successful endoscope surgery, it is desirable that the endoscope or the instrument inserted in the body cavity be manipulated in a space as broad as possible. The endoscope or the instrument can be so manipulated by the use of a manipulator with a multi-joint insertion section which has a high degree of freedom. For example, the master-slave surgical manipulator system disclosed in Jpn. Pat. Application 6-131810 may be used to set an endoscope and a medical instrument at a desired position and orientation within a body cavity.
The master-slave manipulator system comprises a slave section and a master section. The slave section comprises a scope manipulator holding an endoscope and an instrument manipulator holding a medical instrument. The master section comprises a head-mount display and a master arm. To perform an endoscope surgical operation, a surgeon wears the head-mount display and holds the master arm. As the surgeon operates the master arm, the instrument manipulator is moved in the same way as the master arm. As he or she moves the head, the scope manipulator is moved in the same manner as the surgeon's head. Thus, the surgeon can carry out an endoscope surgical operation in the same way he or she would perform laparotomy.
Needless to say, the distance and speed the master arm and the head-mount display are moved totally depend on the surgeon's habit. Preset in the surgical manipulator system described above are fixed control parameters, such as a scale ratio between the moving amounts of the master arm (or the head-mount display) and those of the slave arms (i.e., the scope manipulator and the instrument manipulator) and the response of the slave arms to the motion of the master arm (or the head-mount display). Inevitably, the surgeon needs to be trained to operate the master arm such that the slave arm would move in the very way he or she wants. Unless the surgeon is so trained, it will take him or her much time to perform an endoscope surgical operation by using the surgical manipulator system.
It is desired that an endoscope and a medical instrument, either held by a slave manipulator, be inserted into a body cavity through the holes cut in the body wall and be moved within the body cavity, without applying an excessive force at the holes. To this end, the endoscope may be held by a scope holder of the type disclosed in, for example, Japanese Patent Application 4-221571. The scope holder is designed to hold an endoscope at an appropriate position with respect to the hole cut in the body wall, while the endoscope is being inserted through the hole into the body cavity.
Japanese Patent Application 62-134503 discloses an apparatus which controls a microscope holder by mechanical means, so that the focal point of the surgical microscope may be located at the specified point on the patient's head throughout stereotactic surgery. Japanese Patent Application 1-257907 discloses an apparatus which is used in combination with an X-ray CT scanner and which can orient a medical instrument to the center of an imaginary spherical surface which surrounds the object of stereotactic surgery. Japanese Patent Application 4-51778 discloses an apparatus designed to position a microscope in an imaginary spherical surface which surrounds the object of stereotactic surgery such that the focal point of the microscope is placed at the object.
The scope holder disclosed in Japanese Patent Application 4-221571 must be mechanically adjusted to allow the endoscope to pass through the hole made in the body wall. The mechanical adjustment required is cumbersome. Further, the link mechanism, which is used to guide the endoscope through the hole into and out of the body cavity, has a complex structure and occupies a large space.
The apparatus disclosed in Japanese Patent Application 62-134503 is difficult to operate since it must be mechanically adjusted, too, to locate the focal point of the surgical microscope at the specified point on the patient's head. The link mechanism, which is employed to locate the focal point, is complicated in structure and is large in size, occupying a large space.
The apparatus disclosed in Japanese Patent Application 1-257907 also require mechanical adjustment in order to orient a medical instrument to the center of the object of stereotactic surgery. This mechanical adjustment is complex. Further, the link mechanism, used to orient the instrument, has a complicated structure and occupies a large space.
The apparatus disclosed in Japanese Patent Application 4-51778 has electric motors which are controlled to place the focal point of the microscope at a specified point on the object of stereotactic surgery. The application, however, does not teach how to translate the movement of a joystick into the control of the motors.